ANNOUNCER: Ladies and gentlemen, please welcome to the stage your hosts for this evening Jad Abumrad and Robert Krulwich!

[APPLAUSE]

JAD ABUMRAD: I'm Jad Abumrad.

ROBERT KRULWICH: I'm Robert Krulwich.

JAD: This is Radiolab.

ROBERT: And a while back, we were on stage. We were live at the Paramount Theater in downtown Seattle. This was several years ago. We called that show Apocalyptical, because it was about endings -- different kinds of endings of different things.

JAD: It was a show that we did with all of these incredible musicians and video artists.

ROBERT: And we had puppets. We had huge ...

JAD: Yes.

ROBERT: ... puppets. All of which you can see on the video on our website at Radiolab.org.

JAD: But what we're gonna do for you now is play you part of that original show. Actually, the first story in that show, which is about the end of the dinosaurs.

ROBERT: Because we -- we have news to tell you about that story and its verisimilitude.

JAD: Yes.

ROBERT: So we're gonna go first play you part one of our show about dinosaurs. Let's go back to the Paramount Theater in Seattle. Here we go.

JAD: Okay, we're going to start you off with a guy. Well, the guy who started it off for us. It's a guy named Jay.

JAY MELOSH: Jay Melosh, professor at Purdue University. And I study impact craters among other things.

JAD: Not only can Jay Melosh create impact craters with his mind, but he and his colleagues have been investigating this moment almost as if it were a crime scene that happened not 60 million years ago, but yesterday. And the story that they've put together, it's more than just interesting, it's frankly -- frankly terrifying. And weirdly specific, as it happens. Take for example, the seemingly simple question of when? When did it happen?

ROBERT: You don't mean, like, the year, because that would be a little too specific.

JAD: No, I don't know if you remember, but Jay got even more specific than that. This was a casual question that I threw out. Listen to his answer.

JAD: By the way, do we know anything about seasons? Was this a warm -- a particularly warm ...?

JAY MELOSH: Actually, it was between -- well, this is a bit of a stretch, but it was sometime between June and July.

ROBERT: Really?

JAD: How can you say that so specifically?

ROBERT: How would you know that?

JAY MELOSH: The reasoning is we -- we can, for example ...

JAD: This was the -- this was the first surprise. It's kind of a controversial idea, but basically goes like this. Jay says scientists have found some pollen in rocks which date from that time. Two different kinds of pollen. And based on an analysis of those two kinds of pollen ...

JAY MELOSH: We know that the impact took place between the flowering of the lotus and the flowering of the water lilies.

JAD: Whoa!

ROBERT: Okay, so that's a lotus you see flowering on the left. That's a water lily flowering on the right.

JAD: You can see this if you look at our video online.

ROBERT: Fossils found at the impact site that had pollen from both of these flowers in the same rock would suggest that the impact did in fact take place ...

JAY MELOSH: Somewhere between June and July. It's one of those things in geology, we get a glimpse of a moment far, far back in time.

JAD: So let's go deeper into that moment. All right, everybody. Let's collectively rewind our minds back in time tens of millions of years into the past. 66 million years ago, to be precise. There they are, majestic beasts hanging out on the plains eating their lotus leaves. Sometime in June. June 17th, let's say. And everything on this day ...

JAY MELOSH: Pretty much normal. This particular, fateful day was no different than any of millions and millions of previous days, as far as the dinosaurs were concerned. But if there were any astronomers at the time -- which there weren't -- they might have had some inkling that something was coming, because ...

JAD: Had they looked up ...

JAY MELOSH: They would have seen ...

JAD: A tiny little ...

JAY MELOSH: ... dot of light in the sky. Whereas planets, the moon, move with respect to the stars, this would have had a constant bearing. And an old seaman could tell you that if you see something constant bearing, that's on a collision course with you.

JAD: And that thing, of course, is our asteroid.

JAY MELOSH: Zeroing in on the earth.

ROBERT: I want to say that we do know quite a bit about this asteroid. From the size of the crater and from the amount of certain minerals found at the impact site, we know that the asteroid was roughly six miles wide. And then again, roughly six miles long, which makes it approximately the size of Manhattan Island ...

ROBERT: That is Doug Robertson, a geologist who knows quite a bit about this asteroid.

DOUG ROBERTSON: And by the way, it has a name. It's -- the asteroid's called Baptistina.

ROBERT: Baptistima? Why?

DOUG ROBERTSON: -Stina. Baptistina. I don't know. They name asteroids. On another subject, we do know that the Earth's moon was probably produced by a collision with something the size of Mars.

JAD: Whoa!

JAD: I just threw that in because it's cool. It doesn't really relate to our story.

[AUDIENCE LAUGHS]

ROBERT: We don't have the whole evening here. Let's just stay to it. Okay, the dinosaurs are here on Earth. They're eating their leaves. Meanwhile up in space, our asteroid Baptistina is now hurtling towards the Earth.

JAY MELOSH: 20,000 miles an hour.

ROBERT: Very fast.

JAY MELOSH: 20 times faster than a very fast rifle bullet.

ROBERT: And scientists couldn't be sure what would happen -- mathematically, I mean -- when a Mount Everest-sized bullet traveling at 20,000 miles an hour hits our atmosphere.

JAY MELOSH: The atmosphere is really just a very, very thin skin over the rest of the earth.

JAD: So scientists thought, "All right, if we're gonna construct this story, let's just take it piece by piece and first figure out what would happen when this big ball hurtling through space slams into our atmosphere, which is made of gas, of course. So just to approximate, let's fire a bullet through some gas ...

[GUN FIRING EFFECT]

JAD: ... and watch what happens. Now here, we basically showed a super slow-motion video of a gun firing a bullet underwater. You can see it on our website Radiolab.org. It's very beautiful. You can see the bullet coming out, and freeze it right there at the edge, okay? Basically what you see is this bullet steaming through the water. And by the way, we use water as an approximation for gas, because in gas you would have the same effect I'm about to describe. Creating a wake behind it, and the wake gets wider and wider as it trails away from the bullet. And if you imagine this shape in three dimensions, really what you're looking at is a kind of a cone, like a funnel shape. And inside the -- the walls of the funnel, inside that cone is nothing.

ROBERT: Nothing.

JAD: Nothing.

ROBERT: Because it -- because it's in water. So you saying there's -- it's like a hole in the water.

JAD: That's what I'm saying. There's nothing in there. It's a vacuum in there. Because the bullet is shooting through the water, it pushes the water out of the way. And for a beat, the water doesn't have time to come back together. And so all you have is emptiness in there. Right there, this -- what you're seeing is a massive hole in the water created by a tiny little bullet. Now imagine that that bullet is six miles wide, and the hole that it's making is right above your head.

ROBERT: What does that mean if you're a dinosaur looking up? What would happen?

JAY MELOSH: Well, if you were in the right place -- and this is going to be the wrong place in a second or two.

ROBERT: [laughs]

JAY MELOSH: If you were in the right place to look behind the asteroid as it came in, you'd probably be able to see clearly through to space.

JAD: What? Does that mean you would suddenly be looking at a nighttime hole in a daytime sky?

JAY MELOSH: Right.

ROBERT: Whoa!

JAD: And to be fair, Jay did tell us that you would need special kinds of eyeballs to see this night hole in the day sky, and the dinos didn't have that, so -- it's science! Still. I mean, just imagine what a last image that would be to see day and night come together in the same moment. But according to Jay ...

JAY MELOSH: You better not blink, because before you could open your eyes again ...

[EXPLOSION EFFECT]

JAY MELOSH: ... the asteroid would have hit the surface. And if you were in a position to see that, then you're going to be engulfed by the violence that is just about to occur.

[AUDIENCE LAUGHING]

JAD: By the way, the audience was just laughing at a dinos de los Muertos graphic that just came on the screens.

ROBERT: So we know it was a big explosion. Fine. It was violent. Fine. But I think we should be a little bit subtle about this, because obviously if an asteroid is the size of Manhattan and it lands on your head, you're not gonna feel very good about that. But if Manhattan is -- is hitting the planet Earth, that's a little bit like a pebble hitting an enormous beach ball.

JAD: Yeah, and I can imagine that the little pebble-sized -- relativistically-speaking, the pebble would create some damage in the spot where it landed.

ROBERT: But let's suppose that you are a leaf-eating, mother-of-three hadrosaur living in New Zealand, right? And you're just, at the moment that the asteroid comes in, you're on the -- you're antipodal, you're on the other side of the planet. Would you have any idea that this was happening?

JAD: Well, that's the next question that we took to Jay. How much damage would this thing actually do?

JAY MELOSH: Well, we can do experiments. We can produce things, situations like this in small quantities in the laboratories.

LAB OPERATOR: Okay, you're all set in there?

JAD: Which brings us ...

PETER SCHULTZ: Yeah, we're good to here. You good?

JAD: ... to this guy.

PETER SCHULTZ: I'm Peter Schultz. And I like to do impact experiments.

JAD: Pete Schultz basically has every 13-year-old's dream job. He gets to blow shit up for a living. Basically, what Pete does is he works at this place that you're seeing right here on the screen. This is the NASA Ames Laboratory in California. And the thing that they're putting together there in the middle frame? That is a giant, three-story tall cannon.

ROBERT: What Pete does is he takes projectiles. So for example, you're gonna see him take a little glass bullet over there and he's gonna load it into the top of the cannon, and then he's going to fire it right into a stand-up for planet Earth, which for him will be a sandpit.

JAD: And lucky for us, when we called Pete he was just about to pull the trigger on this thing.

ROBERT: So your -- we're calling you on a day in which you are trying to re-experience the day?

PETER SCHULTZ: Okay. Hold on. We gotta -- we gotta assume the position. We have to cross your fingers.

LAB OPERATOR: Okay, here we go. We got it.

PETER SCHULTZ: Here we go. Here we go.

LAB OPERATOR: We have all of our ready lights. Here we go. Rolling.

[EXPLOSION]

PETER SCHULTZ: That is gorgeous! That -- oh, my gosh!

ROBERT: Is that -- you have instant playback?

JAD: What just happened?

PETER SCHULTZ: Oh, my gosh!

JAD: That is the sound of a man very happy with his explosion.

[AUDIENCE LAUGHS]

PETER SCHULTZ: You can see every piece of this -- of what's happening.

ROBERT: So based on experiments like this, people like Pete can figure out precisely what happened when the asteroid hit the earth. They can quantify the explosion's power by basically leveraging up experiments like this. So according to Doug, the amount of energy that would have been unleashed when that thing came rushing in onto Earth is roughly this.

PETER SCHULTZ: It would hit the Earth with an explosion that's a hundred million megatons.

JAD: Don't look at her wrong or she'll do that to you. Okay, so here's essentially how Doug broke that down for us. Two tons of TNT. We're talking tons here, not megatons. Two tons of TNT will essentially do this.

[FOOTAGE OF BUILDING COLLAPSING]

JAD: On one of the three screens, you see a 10-story building imploding. Two tons of TNT will take down a building. Now, 15,000 tons of TNT? That is what the United States dropped on Hiroshima in 1945. On a second screen, we see archival footage of the atomic bomb. That chaos is 15,000 tons of TNT. Now these days, according to Doug Robertson, a hydrogen bomb ...

DOUG ROBERTSON: Current hydrogen bombs are typically of the order of one million tons of TNT equivalent.

JAD: Now, one million tons of TNT equivalent, that's what we call a megaton. And if you remember, Doug said that the asteroid impact was equivalent of 100 million megatons. So really what he's saying in concrete terms, is that that impact was the equivalent of 100 million of those bombs going off all at once in the same spot.

ROBERT: Which is a lot.

[AUDIENCE LAUGHS]

JAD: That is true. That is true. However, it means -- it really depends on what you mean by "a lot," because I was doing a little Googling and I was surprised to learn that 110-million megatons is not nearly enough to destroy the planet. To destroy the entire planet, you would need -- you ready for this? 110-quadrillion megatons of TNT, which is a hundred million times 110 million megatons of TNT. So going back to your hadrosaur situation, mother-of-three in New Zealand? If the thing came in antipodal to her, maybe she would feel the ground shake a little bit, but after a minute she'd be like, "Whatever," and she'd go back to eating leaves. She probably wouldn't notice it.

ROBERT: Well, no, no. because that's not what we were taught in homeroom by Mrs. LeGrew, or whoever your teacher was. Here's the classic explanation: there was an impact of course, and it kicked up an enormous amount of dust. You'll remember this. The dust then kind of covers the planet. It blankets the earth, makes the Earth very cold, makes the Earth very nasty. All the big plants die. The little plants get sick. The dinosaurs get hungry. The dinosaurs get sick. And then gradually, you know, they get dead. Deader and deader and deader from different things. 10,000 years, 30,000 years, 40 -- until you get, like, oh, 900,000 years later and you've got a shivering, last dinosaur sitting there in the cold going, [SNEEZING SOUND]. And that's the end. That's the story we were told in school.

JAD: Is a long, slow, wintry collapse.

ROBERT: Yeah.

JAD: No!

[BUZZER SOUNDS]

JAD: No. Why would we tell these good people that tired old story from Mrs. -- what is it, Mrs. McGruder's?

JAD: Based on new science. So all right, here's we're gonna do. Keith, pull up that ballistics video that we showed earlier with the red sand. Can you sort of pull that up and blow it up to the three screens? And then yeah, rewind it back.

[VIDEO REWINDING]

JAD: Thank you. No, back just a bit more. All the way to the beginning. Okay, so this is a 6,000-frame-a-second video that you're seeing here. This is from Pete's lab. At this point on the screen, all you're seeing is a pit of red sand. Now, what you see in the first few frames is you see the laser hitting right there, red sand flying in the air, super slo-mo. And then the next frame forward? Right there. You see some fire. You see a little bulb of fire erupt near the impact site. Right where the laser hits the sand, there's this little clump of flame and we freeze on that spot.

JAD: Now, scientists could now measure the temperatures in that spot right there.

ROBERT: Oh, there it is.

JAD: Yeah, right there. And just to state the obvious, we know from those measurements that that spot right there would have gotten very, very, very, very, very hot.

JAY MELOSH: You know, way beyond the temperature of the sun. I mean, we're talking temperatures, maybe 20,000 degrees.

ROBERT: Whoa!

JAY MELOSH: The sun's temperature's about 5,000 degrees.

JAD: And if we're talking temperatures four times hotter than the sun, well anything that's that hot is going to instantly, instantly turn to ...

JAD: So imagine this thing comes barreling in, this asteroid. It doesn't just bounce off the Earth, it plows into the earth. It goes into the surface. Two miles in, five miles in, seven miles in, 10 miles in, 20 miles into the Earth it goes. All the rock that it's plowing into is turning into a liquid, and then into a gas. And now watch what happens next? This is a basic physics experiment we're gonna show you.

JAD: On the screen, you see a very lovely video actually, of a hand dropping a metal ball into some sand.

JAD: This is just a dude dropping a ball in some sand. Watch this right here. Ball goes in, and like a millisecond after it makes impact, disappears into the sand, a little spear of sand goes shooting back in the opposite direction. Sort of a bounce-back effect.

ROBERT: Does -- does this always happen? This -- whatever this is?

JAD: It's like Newton's Law of Something.

ROBERT: Yeah.

JAD: Newton's Law of Sand, let's say. No, but what you see is, you see this fine plume of sand go shooting back in the opposite direction as a sort of rebound, right? Now imagine that that ball is an asteroid, and that sand over there? That's the planet Earth. So Keith, play that one more time.

JAD: We play the video again, but this time as the ball drops, it gradually morphs into an asteroid.

[ROBERT MAKES EXPLOSION SOUNDS]

JAD: Thank you for those sounds. So, but you would get the same effect. You would get the ...

[AUDIENCE APPLAUDS]

JAD: The simple point is ...

ROBERT: It's just something we do.

JAD: You wonder where we get all of our sound design? It's out of that man's mouth, that's where. So you would get that same bounce-back effect of a fine plume shooting back in the opposite direction. But we know -- we just heard Doug describe that it would not be -- it would not be sand in this case. It would be rock gas.

JAY MELOSH: This plume of hot gas expands upward and pushes right on through the atmosphere up into space.

DOUG ROBERTSON: Some fraction hit the moon.

ROBERT: Really?

JAD: You're kidding!

DOUG ROBERTSON: Some fraction of that hit Mars.

JAD: Okay, so now you got this sneeze of rock vapor, it's out in space. Basic physics says that as it travels out farther away from the Earth what's going to happen is it's going to start to cool down a bit. And when it cools ...

DOUG ROBERTSON: It re-condenses into little droplets of that basically formed glass very quickly. Little droplets of glass about the size of sand.

JAD: Now, if you look at one of these little droplets of glass under a microscope, this is what it looks like right there.

JAD: On the screen, you see what looks kind of like a translucent snowball.

JAD: That is actually a magnified image of one of these bits of glass that fell from space that day. Most of them didn't land on the ground. I'll talk about that in a second. But there it is. I don't know about you, but I find that totally terrifying. Because that's -- it looks like a little Baptistina, right? Tiny little asteroid. Except now imagine trillions of these things in a cloud, in a cloud of shrapnel. Going out, out, out, away from the Earth. And what's gonna happen next is that it's gonna start to lose momentum, that cloud. And when it does, the Earth's gravity is gonna grab back hold of it and say, "Come on back."

DOUG ROBERTSON: And 90% of them come back to the Earth.

ROBERT: Well, does falling glass do harm?

DOUG ROBERTSON: Yes. Because what happens is that the -- the glass out in space starts to spread out, like north and south and east and west. And eventually, it will appear in the sky over New Zealand.

JAD: It's now a global phenomenon. And you know, it's really hard to imagine what the hadrosaur would have seen. But the thing to keep in mind is that these things as they're coming in, these bits of glass, 90-some odd percent are burning up in the atmosphere. So very few of them are hitting the ground. So from her point of view, probably would have looked like the greatest meteor shower anyone has ever seen. With one significant bummer, which is this: when these little bits of glass come in, each one that burns up is depositing a little bit of heat into the sky. And collectively, there's such a massive rain of these things coming in ...

JAY MELOSH: Well, the heat would build up. The sky would turn red. It would be getting hotter and hotter.

JAD: And at a certain point, Jay wondered, "Well, how hot exactly would it have gotten?" Like, how much heat exactly would have built up there in the sky and then started to radiate down?

JAY MELOSH: We calculated the amount of heat that would come down. A number. 10 kilowatts per square meter. And yeah, okay. Well, we get this number. Well, what does that mean? Well, I went home and I hooked up a -- a current meter and tried to measure the amount of heat produced in my oven for different amounts of power. And I could get about seven kilowatts per square meter in my oven on broil. And ...

JAD: Like, 500 degrees broil, you mean?

JAY MELOSH: Yeah. But that wasn't quite enough.

JAD: Not nearly. So Jay started measuring other kinds of ovens.

JAY MELOSH: And I finally found out that the heat would be, in fact, like being in a pizza oven. A pizza oven is about right.

JAD: Which means that if you were a terrestrial dinosaur anywhere above the ground on the Earth on that day, you would have experienced some heat that is almost unimaginable. Maybe it started at a hundred degrees, because it was June. It was summer. But within minutes, it would have been 300 degrees. 500 degrees. 700 degrees. 900 degrees. Estimates are on that day, temperatures topped out at something like 1,200 degrees. At that temperature, nothing can protect you. Your scales, your fur, whatever you got, it's not gonna do any good. Your blood will literally start to boil inside your body, and you will die.

[MUSIC]

JAD: So essentially, according to this theory, the dinosaurs and everything else on Earth that day would have been incinerated. And Doug thinks that's what did them in. Not so much the impact, but all that ejecta that went up into the sky, came down as glass rain and created that heat. That's what did them in. And he would argue, it didn't just do some of them in, or even many of them in. He would say it did all of them in, all at once.

DOUG ROBERTSON: There is zero evidence that any dinosaur made it through.

JAD: And the crazy part of this theory is that Jay and Doug think that the whole process, from the impact of the glass rain to the incineration of all of these species on the planet?

DOUG ROBERTSON: It would have taken a few hours.

ROBERT: His best guess? He thinks maybe two hours.

JAD: I mean, that's less time than a -- a business lunch.

ROBERT: Yeah. You try getting east, northwest, anywhere on Mercer Street at rush hour in two hours? You can't do that.

JAD: I mean, if you think about it, that is less time than you will spend in this theater tonight.

ROBERT: That means that you're saying that an animal that had been supreme on the planet for 200 million years disappears in a few hours completely.

DOUG ROBERTSON: Yes.

JAY MELOSH: Yep. That's what the evidence suggests. That's right.

ROBERT: Well, you can consider the evidence, but also you can consider common sense. I mean, we've got a world filled with terrestrial dinosaurs. They were on every continent, they were even in Antarctica. And to say that they all disappeared in two hours? I mean, all? That would -- that suggests that there's none of them in -- out of harm's way. None of them in a cave somewhere, none of them in a grotto, none of them in a -- in a protected forest of any kind. I mean, the word "all" in that connection is just too much. I just don't buy it.

JAD: Well, yeah. I mean, the truth is that the science is never gonna be so exact as to say yeah, all of them disappeared. Or it happened on a single day, or on an afternoon. I mean, no -- no tool that we have is that precise. But what Jay is saying is that it happened fast, very fast. Nothing made it through. What I find interesting is that ultimately, you don't need the ballistics or anything we've shown you so far to know that something major and sudden happened, because you can see evidence of it literally etched into the Earth.

KIRK JOHNSON: So here's the spot where we first found the K-T boundary.

JAD: You can see it really well out in Colorado, actually. We sent one of our producers Molly Webster out there to meet a paleontologist named Kirk Johnson. They hiked over a couple of hills. They found this one specific spot.

MOLLY: I'm like, ready for a dinosaur to come around the corner.

JAD: And ...

MOLLY: Give me a minute.

JAD: ... they started to dig.

MOLLY: So we're digging down, like, a foot at this point, from where we were?

KIRK JOHNSON: Turns out for every three feet, you go down 10,000 years in time.

JAD: See, the Earth has layers. Kind of like a tree has rings. And every three feet down you go, you're going back in time about 10,000 years. And when you go all the way down, all the way back to 66.09 million years, you will find this one little skinny strip of rock.

KIRK JOHNSON: That's the K-T boundary.

MOLLY: That.

JAD: This one skinny gray line.

KIRK JOHNSON: This -- this gray, crappy ...

MOLLY: Oh, that!

KIRK JOHNSON: This ...

JAD: Now in a very real way, that line that you're seeing, that represents the day the asteroid hit. The day. Just above that line?

ROBERT: That's a little bit after the day?

JAD: Just below that line?

ROBERT: Is a little bit before the day.

JAD: The line is called the K-T boundary, and what's cool is you can actually touch it. You can touch evidence of that moment. And in fact Kirk, what he did that day was he took his finger and he dug a piece out and he handed it to Molly.

JAD: And in that mudstone, you'll find all kinds of things. I mean, you'll find very rare minerals like iridium that probably came in on the asteroid and got smushed into that line. Those little glass balls I was talking about? Those little hell balls? Well, if you get out a microscope and you look at that rock, you will see them in there.

[AUDIENCE LAUGHS]

JAD: We put up a funny cartoon of the little hell balls.

JAD: They're all in that line.

MOLLY: How thick do you think that line is?

KIRK JOHNSON: It's about an inch.

MOLLY: Is, like, hidden in there, is sort of the story of that day?

KIRK JOHNSON: Absolutely.

ROBERT: And here's the crazy thing. If this is the line right here, this little strip here.

JAD: Robert traces a picture of the K-T boundary with his finger.

ROBERT: And then you dig just below the line, you are gonna find over and over again dinosaurs everywhere. I mean, they're not gonna be alive, of course.

JAD: He starts putting some toy dinosaurs under the line and making the move.

ROBERT: By giving them a certain amount of energy, which I shouldn't. But they're fossils. And you will find dinosaur fossils from Europe and Idaho and Montana. This one says it was made in China.

[AUDIENCE LAUGHS]

ROBERT: But maybe just go above the line, you don't find any dinosaurs. So below the line -- scientists have looked everywhere above the line, and they haven't -- well, everywhere they have looked anyway, they found nothing. Nothing. Nothing.

KIRK JOHNSON: It's a different world. That's the amazing thing. It's a different world. And it's pretty rare to go, "This is one world, and that's another world."

JAD: This is another moment where I would urge you at some point -- not now, keep listening. But at some point, watch the video of this performance, because what Sarah, Darin, Glenn and Keith do in this moment visually, it's pretty amazing.

ROBERT: Okay, so that was the story we told about the end of the dinosaurs live at the Paramount Theater in Seattle, Washington. When we come back -- we're gonna take a quick break right now, but when we come back, our reporter Molly Webster and I will dish about what we have just learned about that day, those hours, so long ago. We have a whole -- no, I'm not going to tell you this.

JAD: Yeah, don't tell them.

ROBERT: You just have to stay around. It's coming up in just a minute.

MIKE BELL: This is Mike Bell from Newton, North Carolina. Radiolab is supported in part by the Alfred P. Sloan Foundation, enhancing public understanding of science and technology in the modern world. More information about Sloan at www.sloan.org.

JAD: This is Radiolab. I'm Jad.

ROBERT: I'm Robert. We are back. Now you just heard our drastic, in-the-moment version of the day the dinosaurs all died. And now ...

MOLLY: Do you think you're thinking of something different?

ROBERT: No, no, no. It was some guy who's sort of an amateur, and he was -- he went to South Dakota.

ROBERT: We have an update ...

MOLLY: Maybe you should brain dump to me.

ROBERT: ... from our reporter Molly Webster, who reported that story for us way back when. And now she is here again with the news.

JAD: Very interesting news.

MOLLY: Well, so we're updating the Apocalyptical episode.

ROBERT: Right.

MOLLY: Which was probably the last time I saw you. It was six years ago. I don't know. And -- and the reason we're updating it is because this Science article came out that basically, if it proves to be true, it could be one of the largest paleontological discoveries of the day the dinosaurs died.

ROBERT: Day?

MOLLY: Mm-hmm. It claims to tell the story of the first 15 minutes to three hours after the asteroid hit down in Mexico.

ROBERT: Wow!

MOLLY: And basically what it is is a geologic formation that is kind of like that line that we saw in Colorado, but, like, that line on steroids. And it's in the southwest corner of North Dakota.

ROBERT: Which is not close to Central America.

MOLLY: It's not close to -- it's not close to the Gulf of Mexico at all. It's like, 3,000 kilometers away. And this particular site used to be I guess, the assumption is 66 million years ago that it was kind of like a riverbed, like a river valley that was muddy and warm. And it was near something called the Western Interior Seaway.

ROBERT: So then what did they find there?

MOLLY: So one of the authors on this paper is this super-famous paleontologist, Jan Smit. He said when he went to the site and he stood there, he's like, "What I see in this place is a three-hour story of that day with all the victims. And it feels like a movie is playing out before me."

ROBERT: Oh, so he can sort of turn it into a scene-by-scene-by-scene adventure in time?

MOLLY: Yeah. So the story that they lay out in the paper is that this area within, like, 15 minutes after the asteroid, it was hit by waves from the Western Interior Sea. And they brought with them saltwater fish and, like, seashells and things, like, into this freshwater area. And then at the same time, remember, like, we talked about those glass balls that fell from the sky?

ROBERT: Yes.

MOLLY: So the story that this area tells is that there are actually kind of like three phases of those glass balls of various, like, size and proportions. And some that went really, really far into, like, space, and came back. And so they came back later than all the other ones, and are more -- you know, it's funny. It's like all glass balls in the end, really? But -- but, like, if you're a paleontologist, you're really geeking out right now over, like, the different types of glass balls that this site holds.

ROBERT: But these -- these glass balls are basically the spill of the giant crash, right?

MOLLY: Yeah. And some of them are actually made of particles from the actual impact site.

ROBERT: Oh, wow!

MOLLY: And, like, in all of the previous sites they had found in the United States, none of those glass balls were actually still glass. They had decomposed into clay. Apparently glass will change into clay over time. I did not know this. But in this location, they actually have glass unaltered by the passage of time. So it holds within it, like, the air and geochemistry ...

ROBERT: Of that day?

MOLLY: Of that day and that place. And they found some that were actually -- I feel like this is such a Jurassic Park moment, they found some that were trapped in amber.

ROBERT: Mm-hmm.

MOLLY: That haven't -- that are totally unaltered.

ROBERT: Wow!

MOLLY: And I was just like -- I really don't know anything except for that, like, Jurassic Park made me think that anything in amber is really important!

ROBERT: And very old!

MOLLY: Very old! And, like ...

ROBERT: And frozen in time.

MOLLY: And holds -- holds all of the memories of Mother Earth.

ROBERT: And just to back up for a second. The site itself, back in the -- back in the -- on the day that this -- this asteroid hit the earth, that was a tropical, well-populated place?

MOLLY: Yeah. So, subtropical, well-populated.

ROBERT: So it would have dinosaurs, and it would have ...

MOLLY: Yeah, so it would have dinosaurs, it would have fish. It seemed to be covered in trees. Insects, lots of insects. Mammals ...

ROBERT: Little, little mammals, right?

MOLLY: Yeah, whatever our oldest mammal was. Yeah, so it was a really, like, lush, happening area. And what they see in this site that they've uncovered today, is what appears to be instantaneous death. They've described fish that are stacked -- dead fish, fossilized fish that are stacked like logs. And it's freshwater fish and marine fish. And they do describe it as, like, a mass grave. There are fish fossils, like, wrapped around tree bases.

ROBERT: Like -- like, creatures and plants and stones and pebbles and shellfish and everything, saltwater, freshwater. Everything all smooshed together.

MOLLY: It feels like a tumble of life that was, like, thrown -- like, almost, like, thrown together in a wash and, like, mixed up. You know, if you're a -- if you're an animal in that moment, you're there, and something happens in Mexico, and you have no idea.

ROBERT: Right.

MOLLY: But maybe about 15 minutes after that thing happens in Mexico that you have no idea about, you might feel the earth rumble.

ROBERT: Hmm.

MOLLY: There's some shaking. And then that rumbling, that shaking, comes with it a big wave from the sea.

ROBERT: Whoa!

MOLLY: And so you get this big whoosh that comes in. And then what happens is that whoosh comes in, is you're already starting to get the glass balls from the heavens. And so -- and what they see is you get this, like, wave of kind of what seems to be almost like raining glass balls. And then that's, like, mixed in with the mud from, like, the tidal surge, and the layers of things that are dying. And the fish? Like, some of the details that stand out to me the most are the -- the fish are all generally pointed in the same direction, and they're, like, stacked pretty tightly, mouths open and their fins splayed.

MOLLY: But one of the things I think is super cool is that all that different stuff we talked about happening across the globe in our original show? Like, it probably got really hot. Like, you know, that was Jay Melosh who was like, it was really hot. Doug Robertson was talking about, like, the boiler -- the boiler effect. And then we talked about that flash of blue light, and we talked about things raining from the sky, and we talked about June or July, all that stuff. A lot of that stuff was based on really smart models. This seems to be a place that actually will provide evidence either for or against those models. Like charred tree trunks, which I think made, like, Jay Melosh really happy because he was like, "It did get really hot," you know? And then there are, like, the fish wrapped around trees, and then there appears to be a dinosaur bone, and possibly a dinosaur bone with skin still attached. And Kirk Johnson said if that is -- if it really is a dinosaur bone, and that site is connected to the asteroid impact like they think it is, it would be the youngest dinosaur ever.

ROBERT: My last question is, is there something we need to know about the man whose dig this is that would color our feelings about it?

MOLLY: The study's author -- the main author's this guy Robert DePalma. He's in his late-30s. He does not have a PhD. He works a lot outside of normal academia. But Jay Melosh, who was in our first thing, he is the editor on the -- on the article. And then Walter Alvarez and Jan Smit are in the article, are -- are co-authors. And then this other guy, like, Mark Richards, who's, like, a really famous tsunami-earthquake guy. So he -- he's got a collection of people around him. And I think everyone else says, like if the stuff that they say that they have is there, it's amazing. I do think one of the things in the paper, like -- is like, people are like, "You are claiming to know a three-hour window, 66 million years ago. That is a very big claim, right?" You're really gonna have to produce a lot of evidence. And I think that people think it could be there.

ROBERT: Boy, you convinced me. If you got bunches of animal all squished up together all at once, and you've got rain that you can account for in different stages, and that looks like you're right there at the splat moment plus three hours ...

MOLLY: I know. [laughs]

ROBERT: And everything's dead. And the forest is burned. It's like -- it's almost like it's exactly what we said.

MOLLY: I know. I was like, "Well, I'm hooked."

ROBERT: It's just a -- it does leave you at the end of the day feeling a little bit nervous to be on this big, safe, blue dot, recognizing that we are so vulnerable. That life is really fragile, when a pebble can murder.

MOLLY: You know what I think is the crazy part is, if you were an animal standing in North Dakota, you would have no idea what was happening. There's, like -- I like logic. I like to be able to say, "Oh, there's a source, and then a thing happened." And to just be there and all of a sudden the Earth starts rattling like a bell around you, and then a tidal wave comes in and then I'm dead.

ROBERT: The tidal wave comes in when you're not even near the sea.

MOLLY: No! Like, that to me is the most -- is the most stunning part.

ROBERT: The taste of salt on your mouth as you die, thinking, "Now where did that -- is what?"

MOLLY: Yeah, it's just -- it's just like, to just be standing there unawares, and then a thing happens that really has nothing to do with you.

ROBERT: Nothing.

MOLLY: That's the weird part to me.

ROBERT: Thank you, Molly.

MOLLY: Sure!

[EXTRO MUSIC COMES IN]

ANNOUNCER: Apolcalypse brought to you by Sarah Lipstate, Glenn Kotche and Darin Gray!

JAD: I just want to give a very special thanks to the people who shared the stage with us. Sarah Lipstate from Noveller, Darin Gray on the bass, And Glenn Kotche on the drums. They're both from the band On Fillmore. We were so lucky to share the stage with those guys, along with video maestro Keith Skretch, who was doing the live video.

ROBERT: And our brilliant puppeteer Miron Gusso.

JAD: Oh, my God. That guy, so good. Check out all of them at Radiolab.org/live. You can see them doing what they do visually. It's pretty -- it's pretty worth watching.